Video transmission system with timing based on a global clock and methods for use therewith

ABSTRACT

A video transmission system includes a network module that receives network global positioning system (GPS) signals and that transmits a video signal to a remote device that includes time stamps that are based on the network GPS data. A remote device receives the video signal and that plays the video signal based on local timing generated from local GPS signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to the following U.S. patentapplications: VIDEO TRANSMISSION SYSTEM WITH EDGE DEVICE FOR ADJUSTINGVIDEO STREAMS BASED ON DEVICE PARAMETERS AND METHODS FOR USE THEREWITH,having Ser. No. ______, filed on ______;

VIDEO TRANSMISSION SYSTEM WITH AUTHENTICATION BASED ON A GLOBAL CLOCKAND METHODS FOR USE THEREWITH, having Ser. No. ______, filed on ______;

VIDEO TRANSMISSION SYSTEM BASED ON LOCATION DATA AND METHODS FOR USETHEREWITH, having Ser. No. ______, filed on ______; and

MOBILE VIDEO DEVICE WITH ENHANCED VIDEO NAVIGATION, having Ser. No.______, filed on______.

BACKGROUND OF THE INVENTION

Technical Field of the Invention

This invention relates generally to the transmission and processing ofvideo signals and devices that use such video signals.

Description of Related Art

Communication systems provide several options for obtaining access tobroadcast video content. Consumers can receive broadcast standarddefinition and high definition television broadcasts from the air withan antenna. Analog and digital cable television networks distribute avariety of television stations in most communities on a subscriptionbasis. In addition, satellite television and new internet protocol (IP)television services provide other subscription alternatives forconsumers. Analog video signals can be coded in accordance with a numberof video standards including NTSC, PAL and SECAM. Digital video signalscan be encoded in accordance with standards such as Quicktime, (motionpicture expert group) MPEG-2, MPEG-4, or H.264. In addition to digitalcoding, some video signals are scrambled to provide access to thesesignals, only to the subscribers that have paid to access the particularcontent.

The desire for video content has driven cellular telephone networks tobegin offering video programs to their subscribers as streaming video.In this fashion, users of mobile devices can have access to videoprogramming on the go. Some of the techniques used in providingbroadcast video content to stationary devices are not suitable foradaptation to the viewing environment associated with a handheld mobiledevice.

The limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of ordinary skill in the artthrough comparison of such systems with the present invention.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods of operationthat are further described in the following Brief Description of theDrawings, the Detailed Description of the Invention, and the claims.Other features and advantages of the present invention will becomeapparent from the following detailed description of the invention madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 presents a block diagram representation of a video network 102 inaccordance with an embodiment of the present invention;

FIG. 2 presents a block diagram representation of a video network 102 inaccordance with another embodiment of the present invention;

FIG. 3 presents a block diagram representation of a video processingsystem 125 in accordance with an embodiment of the present invention;

FIG. 4 presents a block diagram representation of a video processingsystem 125′ in accordance with another embodiment of the presentinvention;

FIG. 5 presents a block diagram representation of a mobile video device110 in accordance with an embodiment of the present invention;

FIG. 6 presents a block diagram representation of a mobile video device110′ in accordance with another embodiment of the present invention;

FIG. 7 presents a block diagram representation of a mobile video device111 in accordance with another embodiment of the present invention;

FIG. 8 presents a pictorial representation of a mobile device 200 inaccordance with another embodiment of the present invention;

FIG. 9 presents a pictorial representation of a mobile device 200 inaccordance with another embodiment of the present invention;

FIG. 10 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 11 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 12 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 13 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 14 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 15 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 16 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 17 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 18 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 19 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 20 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 21 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 22 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 23 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 24 is a flowchart representation of a method in accordance with thepresent invention;

FIG. 25 is a flowchart representation of a method in accordance with thepresent invention; and

FIG. 26 is a flowchart representation of a method in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 presents a block diagram representation of a video network 102 inaccordance with an embodiment of the present invention. A network 102 isshown that distributes information such as video content 106 from avideo source 100 to a wireless access device 104 for wirelesstransmission to wireless video devices such as mobile video device 110or other video devices. The video content 106 can include movies,television shows, commercials or other ads, educational content,infomercials, or other program content and optionally additional dataassociated with such program content including but not limited todigital rights management data, control data, programming information,additional graphics data and other data that can be transferred inassociated with program content. Video content 106 can include videowith or without associated audio content. The video content 106 can besent as broadcast video, streaming video, video on demand and near videoon demand programming and/or other formats.

The network 102 can be a dedicated video distribution network such as adirect broadcast satellite network or cable television network thatdistributes video content 106 from a plurality of video sources,including video source 100, a plurality of wireless access devices andoptionally wired devices over a wide geographic area. In thealternative, network 102 can be a heterogeneous network that includesone or more segments of a general purpose network such as the Internet,a metropolitan area network, wide area network, local area network orother network and optionally other networks such as an Internet protocol(IP) television network.

The video content 106 can be carried as analog signals such as NationalTelevision System Committee (NTSC), Séquentiel couleur à mémoire (SECAM)or Phase Alternating Line (PAL) coded video signals, or digital videosignals such as Quicktime, (motion picture expert group) MPEG-2, MPEG-4,H.264, or other format, either standard or proprietary that are carriedvia an IP protocol such as TCP/IP, Ethernet protocol, Data Over CableService Interface Specifications (DOCSIS) protocol or other protocol.

Wireless access device 104 can include a base station or access pointthat provides video content 106 to a plurality of video subscribers overa cellular network such as an Universal Mobile Telecommunications System(UMTS), enhanced data rates for GSM evolution (EDGE), 3G, 4G or othercellular data network, a wireless local area network (WLAN) such as an802.11a,b,g,n, WIMAX, or other WLAN network. In addition, the wirelessaccess device can include a home gateway, video distribution point in adedicated video distribution network or other wireless gateway forwirelessly transmitting video content 106, either alone or inassociation with other data, signals or services, to mobile video device110 and/or video device 112.

Mobile video device 110 can include a video enabled wireless telephoneor other handheld communication device with wireless connectivity via awireless data card, wireless tuner, WLAN modem or other wireless link ordevice that alone or in combination with other devices is capable ofreceiving video content 106 from wireless access point 104 and storingand/or displaying the video content 106 for a user.

Edge device 105 can include a server, router, such as an edge router,switch, hub, gateway, interworking device or other network module thatreceives a video stream 107 that contains video content 106 andprocesses the video stream 107 to produce a video signal 109 fortransmission to the mobile video device 110. In an embodiment of thepresent invention, the edge device 105 receives mobile device feedback112 such as a device parameter, power state, measurements of channelcharacteristics, location data or other data that can be used by edgedevice 105 in the processing of video stream 107.

The video source 100, network 102, wireless access device 104, mobilevideo device 110 and/or edge device 105 includes one or more features ofthe present invention that will be described in greater detail inconjunction with FIGS. 2-26 that follow.

FIG. 2 presents a block diagram representation of a video network 102 inaccordance with another embodiment of the present invention. Inparticular, a network diagram is shown that includes many similarelements to the network of FIG. 1 that are referred to by commonreference numerals In addition, edge device 115 operates as edge device105, yet is located remotely from wireless access device 104. In thisconfiguration, portions of network 102 transport video signal 109 andmobile device feedback 112 between edge device 115 and wireless accessdevice 104. While edge device 115 is shown as being connected to, butapart from, network 102, edge device 115 can be considered as part ofnetwork 102, particularly in a configuration where network 102 is aheterogeneous network and edge device 115 includes an edge router,gateway, hub or interworking device that converts a video stream 107from a first format, such as a first digital format used in one portionof the heterogeneous network, to another format, such as MPEG-2, H.264or other digital format used to communicate with wireless access device.

The video source 100, network 102, wireless access device 104, mobilevideo device 110 and/or edge device 105 include one or more features ofthe present invention that will be described in greater detail inconjunction with FIGS. 3-24 that follow.

FIG. 3 presents a block diagram representation of a video processingsystem 125 in accordance with an embodiment of the present invention. Avideo processing system 125 is shown that can be used in conjunctionwith network 102.

Edge device 122, such as edge device 105 or 115 processes video stream99, such as video stream 107 or other video stream that includes videocontent 106, to produce video signal 109, optionally based on mobiledevice feedback 112. In an embodiment of the present invention, edgedevice 122 can include a video encoder or transcoder that is implementedusing one or more microprocessors, micro-controllers, digital signalprocessors, microcomputers, central processing units, field programmablegate arrays, programmable logic devices, state machines, logic circuits,analog circuits, digital circuits, and/or any devices that manipulatessignals (analog and/or digital) based on operational instructions thatare stored in a memory module. When edge device 122 is implemented withtwo or more devices, each device can perform the same steps, processesor functions in order to provide fault tolerance or redundancy.Alternatively, the function, steps and processes performed by edgedevice 122 can be split between different devices to provide greatercomputational speed and/or efficiency. The associated memory module maybe a single memory device or a plurality of memory devices. Such amemory device may be a read-only memory, random access memory, volatilememory, non-volatile memory, static random access memory (SRAM), dynamicrandom access memory (DRAM), flash memory, cache memory, and/or anydevice that stores digital information. Note that when the edge device122 implements one or more of its functions via a state machine, analogcircuitry, digital circuitry, and/or logic circuitry, the memory modulestoring the corresponding operational instructions may be embeddedwithin, or external to, the circuitry comprising the state machine,analog circuitry, digital circuitry, and/or logic circuitry.

Wireless access device 104 includes transceiver module 128 that createsRF signals containing the video signal 109 for transmission to mobilevideo device 110 via one or more RF communication channels 149. Asdiscussed above, edge device 105 can receive mobile device feedback 112from mobile device 110 via wireless access device 104. In operation,edge device 105 can generate video signal 109 by adjusting video stream99 based on the mobile device feedback 112. In this fashion, a videosignal 109 can be transmitted to mobile video device 110 that isformatted based on the particular characteristics of that device, adaptsto the particular channel conditions, includes authentication data thatis based on the timing used by the mobile communication device or basedon its location, etc.

In an embodiment of the present invention, the mobile video feedback 112includes a device parameter. In one example, the mobile device feedback112 includes a device resolution, a screen size, and/or other displaysetting that is either inherent to the capabilities of the mobiledevice, have been established by the user of the device based on displaypreferences or that are particular to an anticipated reception of videosignal 109 or display settings that have been established by the mobiledevice itself based on current channel characteristics, power state,error rates, bandwidth, etc. In this fashion, the edge device 122 cangenerate a video signal 109 from video stream 107 with a frame rate,pacing, color depth, data rate, encoding format and/or resolution that aparticular mobile device 110 requires or desires to receive.

In additional mode of operation, the transceiver module 128 includes acontrol module 148 that generates one or more channel characteristics144 based on the conditions of RF channel 149. In particular, controlmodule 148 monitors a signal to noise ratio, signal to noise andinterference ratio, a bit error rate, packet error rate, or otherchannel characteristic and generates a one or more channelcharacteristics 144 in response thereto. In this mode of operation, theedge device 122 adjusts the video stream 99 to generate video signal 109based on the channel characteristic 144 as well as other factors such asmobile device feedback 112. For instance, when the channelcharacteristics are unfavorable, one ore more video parameters such asthe bandwidth, frame rate, color depth or resolution can be reduced byedge device 122 and/or the error detection and correction can beincreased by transceiver module 148 to facilitate accurate decoding ofthe video signal 109 by the mobile device 110.

In an additional mode of operation, the mobile device feedback 112includes a decoding error feedback parameter that indicates a frequencyor amount of decoding errors currently present in the decoding of thevideo signal 109. As described in conjunction of the use of optionalchannel characteristics 144, when the decoding error feedback parameterindicates that the channel characteristics are unfavorable, one or morevideo parameters of video signal 109 such as the bandwidth, frame rate,color depth or resolution can be reduced by edge device 122 and/or theerror detection and correction can be increased by transceiver module148 to facilitate accurate decoding of the video signal 109 by themobile device 110.

In a further mode of operation, mobile device 110 generates mobiledevice feedback 112 that indicates a power state of the device. Forexample, when the mobile device is powered by a battery and enters a lowpower state, edge device 112 can adjust video stream 99 to generatevideo signal 109 with a reduced bandwidth, frame rate color depth,resolution or for black and white operation to conserve power at themobile device. Further, in a circumstance where video stream 99 includesvideo content 106 such as show, movie or other program with a durationor remaining duration if the video content 106 is in progress, edgedevice 122 can respond to a mobile device feedback 112 that includes aremaining battery life to generate video signal 109 by adjusting thevideo parameters of video stream 99 to allow the mobile device toconserve enough power to view the video content 106 to its end, ifpossible. For example, if the mobile device feedback 112 indicates thatthe mobile device 110 has only 10 minutes of remaining battery life atpresent consumption and the video content 106 is a movie that has 12minutes yet to run, the edge device 122 can adjust the video parametersof video signal 109 to conserve power in the mobile device—allowing theall 12 remaining minutes of the video content 106 to be viewed.

In an embodiment of the present invention, edge device 122 is coupled toor otherwise includes a global position system (GPS) receiver 124 thatgenerates network global positioning system (GPS) signals 126. Inoperation, GPS receiver 124 is coupled to recover a plurality ofcoarse/acquisition (C/A) signals and a plurality of navigation messagesfrom received GPS signals from one or more orbiting satellites. The GPSreceiver 124 utilizes the C/A signals and the navigation messages todetermine the position of the GPS receiver 124 and generate GPS signals126 that contain GPS position/location data, clock signals and/orreal-time time and date derived from the atomic clocks onboard one ormore GPS satellites.

In a mode of operation, the edge device 122 uses one or more clocksignals from the GPS receiver 124 as a global clock to aide insynchronizing the transmission of the video signal 109 with itsreception by a mobile device 110 that is also equipped with a GPSreceiver and therefore also has access to the same global clock. Inparticular, edge device 122 can generate video signal 109 based on aclock signal derived from a global clock signal included in GPS signals126. If mobile video device 110 is equipped with its own GPS receiver,it can receive and decode the video signal 109 based on the same globalclock. In this fashion, the transmitting and receiving clock can besynchronized in frequency reducing or eliminating jitter.

In addition or in the alternative, edge device 122 can include timestamps in video signal 109 that are generated based on the global clocksignal. When mobile video device is equipped with its own GPS receiver,the video signal 109 can be decoded and played based on local timinggenerated by its own local GPS signals that include signals generated bythe same global clock. For example, mobile video device 110 can generatemobile device feedback 112 that indicates that it is equipped with alocal GPS receiver and that local GPS signals are available. Inresponse, edge device 122 can generate video signal 109 with timing andtime stamps that are based on a global clock signal included in GPSsignals 126. In addition, edge device 122 can optionally reduce thefrequency of the time stamps included in video signal 109, since thetiming between edge device 122 and mobile video device 110 is based on acommon global clock and is presumably more accurate than ordinarytiming.

In an embodiment of the present invention, edge device 122 further usestiming data derived from GPS signals 126 to generate authentication dataincluded in video signal 109. In particular, edge device 122 can obtainreal-time clock signals such as time and date from the GPS receiver 124in GPS signals 126. This time and date can be included in the videosignal 109. Mobile video device 110 can include an authenticationroutine that compares the time and date from the authentication data toits own time and date, such as a time and date generated locally by itsown GPS receiver. If the time and date included in the authenticationdata compare favorably to locally generated timing (such as when thelocally generated time and date and the authentication data varies byless than an authentication threshold, the video signal 109 can beauthenticated and the playback of video signal by mobile video device110 can be enabled. If however, the time and date included in theauthentication data vary from the locally generated time and date bymore than the authentication threshold, the playback of the videocontent mobile video device 110 can be disabled.

The authentication threshold can be 5 seconds, 10 seconds, one minute ora shorter or longer period based on the desired level of security, theexpected latency of transmission and decoding, etc. In this fashion,video content can be transmitted with authentication to compatiblereceivers for real-time display only. In a further embodiment, a muchlonger authentication threshold, such as one day, one week, etc, canlikewise be used to allow storage of the video signal 109 and playbackwithin the allotted period. As described above, the authentication datacan indicate the time that the data was transmitted, however, theauthentication data can itself include an authorized time period when auser can play the video signal and/or a number of times the user canplay the video signal. When local time and data fall within theauthorized time period and the number of times the video has been playedhas not been violated the video signal 109 can be authenticated and theplayback of video signal by mobile video device 110 can be enabled. Ifhowever, the local time and date fall outside of the authorized timeperiod or the number of times that a video can be played has beenexceed, the playback of the video signal by the mobile video device 110can be disabled.

In an embodiment of the present invention, mobile device feedback 112includes location data from the mobile device that is used by edgedevice 122 in presenting video signal 109. In one mode of operation, theedge device 122 restricts the transmission of video signal 109 toinclude or exclude certain geographical areas, modifies the fee chargedin association with the presentation of video content included in videosignal 109 based on the geographical area and/or adjusts one or morevideo parameters when generating video signal 109 based on thegeographical location that the video signal 109 will be transmitted.

For example, the transmission of particular content 106 may begeographically restricted. In this instance, edge device 122 onlygenerates video signal 109 and/or enables transmission when the locationdata received in mobile device feedback 112 corresponds to an allowedarea. In this fashion, video signal 109 can be prevented from beingtransmitted to black-out cities, countries or other geographical areas.

In another example, the fee charged can be varied based on theparticular location. For instance, the location data can be compared toa rate table associated with edge device 122 and a billing record can begenerated that corresponds to the location of the mobile video device110. Further, the resolution, frame rate, bandwidth, digital format orother video parameters of the video signal can be adjusted based on thelocation data, for instance to correspond to the capabilities of the RFchannel 149 at that particular location. In addition, high qualitypresentations of video signal 109 may only be allowed in certaingeographical areas, and the overall quality of the video signal (asreflected in a choice of video parameters used to generate video signal109) can be varied to correspond to the particular location of themobile video device 110 as reflected by the location data received byedge device 122.

In an embodiment of the present invention, the location data receivedvia mobile device feedback 112 can be used to generate location-basedauthentication data that is embedded in the video signal 109. Mobilevideo device 110 can include an authentication routine that compares thelocation data from the authentication data to its own location datagenerated locally by its own GPS receiver. If the location data includedin the authentication data compare favorably to locally generatedlocation data the video signal can be authenticated and the playback ofvideo signal 109 by mobile video device 110 can be enabled. If however,the location data included in the authentication data vary from thelocally location data by more than an authentication threshold such as 1mile, 5 miles or some greater or lesser distance based on the desiredlevel of security, the playback of the video signal 109 by the mobilevideo device 110 can be disabled. In this fashion, video content 109 canbe transmitted with authentication to compatible receivers for displayonly when the mobile video device is within a certain geographicalrange. If, for instance, the video signal 109 were received, stored andtransferred to another device with compatible authentication at anotherlocation, the authentication routine would prevent the playback of thevideo signal 109.

FIG. 4 presents a block diagram representation of a video processingsystem 125′ in accordance with an embodiment of the present invention. Avideo processing system 125′ is shown that can be used in conjunctionwith network 102. In particular a video processing system is shown thatincludes similar elements to the video processing system 125 presentedin conjunction with FIG. 3 that are referred to by common referencenumerals. In addition, video processing system 125′ includes a videoencoder 120 that encodes a video stream that includes video content 106into a video stream 107. While shown as separate from video source 100,video encoder 120 can be incorporated into video source 100 or can bedownstream of the video source 100 in network 102. For instance, encoder120 can be incorporated in a head-end, video server, edge router, videodistribution center, or any other network element of network 102. Inthis embodiment, edge device 122 includes a transcoding module 127 thatoptionally generates the video signal 109 by transcoding the videostream 107 from a first video format to a second video format. The useof transcoding module 127 provides additional flexibility in edge devicein adjusting the video parameters of video signal 107 when generatingvideo signal 109 as well as altering the overall format when generatingvideo signal 109.

FIG. 5 presents a block diagram representation of a mobile video device110 in accordance with an embodiment of the present invention. Mobilevideo device 110 includes a transceiver module 130 that receives RFsignals containing the video signal 109 and that demodulates and downconverts these RF signals to extract the video signal 109. Video player136 includes a video decoder 152 that generates a decoded video signal154 and a video display device 140, such as plasma display, LCD display,cathode ray tube (CRT), that either directly or via projection, createsa video display for an end-user.

In an embodiment of the present invention, video decoder 152 optionallyoperates in a plurality of modes of operation. These modes of operationcan be selected based on a device parameter 146 received from optionalcontrol unit 150 to conform the decoding of the video signal 109 to theparticular characteristics or the particular state of the device videosignal 109 and the color scale, resolution and/or frame rate, based on aparticular device state, such as the power state of the device.

In particular, video decoder 152 produces a decoded video signal fromthe video signal 109, based on the device parameter 146 provided bycontrol unit 150. The device parameter 146 can include a devicecharacteristic such as the device resolution, frame rate, color scale,black and white or color properties of the display device 140 that arestored in control unit 150 of the mobile video device 110. In addition,optional control module 147 of transceiver module 130 operates in asimilar fashion to control module 148 to generate channelcharacteristics 144 that can also be provided to edge device 122 viamobile device feedback 112 and to decoder 152. For instance, the deviceparameters of a mobile video device 110 may be a high resolution and thechannel characteristics and power state of the device are sufficient tosupport this high resolution. In this case, mobile device feedback 112can optionally indicate the device parameters 146, channelcharacteristics 144 and/or power state to a network module such as edgedevice 122 that generates video signal 109 corresponding to the mobiledevice feedback 112 that is received. Video decoder 152 operates todecode the video signal 109 to generate decoded video signal 154 basedon the particular device parameters 146 and channel characteristics 144.

If however, control module 148 of transceiver module 130 determines thatthe channel conditions do not support a high quality signal, mobiledevice feedback 112 can optionally indicate this to edge device 122 thatgenerates video signal 109 with reduced color depth, resolution, framerate, bandwidth, etc. In this circumstance, video decoder receives anindication via channel characteristics 144 and decodes video signal 109accordingly.

In a further embodiment of the present invention, the control unit 150determines the state of the device, such as a power state and can adjustthe one or more device parameters 146 in response. In this fashion, thecontrol unit can control the video decoder 152 to a lower frame rate,lower color scale or to black and white operation, to a reducedresolution and/or to other state corresponding to a reduced power statethat may include reduced processor speed and reduced computationalabilities, shutting down one or more MIMO channels of the transceiver130 or otherwise reducing the reception bandwidth, et cetera. Thesechanges in reception and decoding based on the reduced power state cansave processing power and help increase battery life.

In addition, video decoder 152 optionally generates a decoder feedbackparameter 149 based on an amount or frequency of decoder errors. Thedecoder feedback parameter 149 is supplied to control unit 150 and canbe used by the control unit 150 to determine the state of the device andto adjust the one or more device parameters 146 in response. In thisfashion, the control unit can control the video decoder 152 to a lowerframe rate, lower color scale or to black and white operation, to areduced resolution and/or to other state to control the decoder feedbackto an acceptable level so that the video player can play the videosignal 109 in accordance with the these device parameters. Decoderfeedback 149 can be included in device parameter 146 that is sent asmobile device feedback 112 to edge device 122.

Video decoder 152 can be implemented in hardware, software or firmware.In particular embodiments, the video decoder 152 can be implementedusing one or more microprocessors, micro-controllers, digital signalprocessors, microcomputers, central processing units, field programmablegate arrays, programmable logic devices, state machines, logic circuits,analog circuits, digital circuits, and/or any devices that manipulatessignals (analog and/or digital) based on operational instructions thatare stored in a memory module. When video decoder 152 is implementedwith two or more devices, each device can perform the same steps,processes or functions in order to provide fault tolerance orredundancy. Alternatively, the function, steps and processes performedby video decoder 136 can be split between different devices to providegreater computational speed and/or efficiency. The associated memorymodule may be a single memory device or a plurality of memory devices.Such a memory device may be a read-only memory, random access memory,volatile memory, non-volatile memory, static random access memory(SRAM), dynamic random access memory (DRAM), flash memory, cache memory,and/or any device that stores digital information. Note that when thevideo decoder 152 implements one or more of its functions via a statemachine, analog circuitry, digital circuitry, and/or logic circuitry,the memory module storing the corresponding operational instructions maybe embedded within, or external to, the circuitry comprising the statemachine, analog circuitry, digital circuitry, and/or logic circuitry.

FIG. 6 presents a block diagram representation of a mobile video device110′ in accordance with another embodiment of the present invention. Inparticular, mobile device 110′ includes many similar elements of mobiledevice 110 presented in conjunction with FIG. 5 that are referred to bycommon reference numerals. In addition, mobile device 110′ includes aGPS receiver 160 that generates GPS data 162 that can be supplied toedge device 122 as mobile device feedback 112 and optionally used byvideo decoder 152 for authentication of the video signal 109. GPS clocksignal 164 can be used as a global clock signal for synchronizing thetiming of mobile video device 110′ and edge device 122, and forcontrolling the timing of the decoding and playback of video signal 109.As discussed in conjunction with FIG. 3, the presence of GPS receiver160 and/or the receipt of current GPS data 162 or GPS clock signals 164can be used by mobile device 110′ to trigger mobile device feedback 112sent to edge device 122 that indicates the availability of GPS data inthe mobile device for the purposes of timing and/or authentication.

In an embodiment of the present invention, the video signal 109 isencoded with timings that is based on GPS signals or some other globalclock. Mobile video device 110′ generates its own local GPS signals thatinclude GPS clock signals 164. Video decoder 152 decodes the videosignal 109 based on local timing generated from GPS clock signals 164.In addition, the decoder can measure one or more timing parameters suchas a network jitter parameter, and a network latency parameter, bycomparing the local timing generated from GPS clock signals and thetiming of the video signal 109 generated by encoding the video signalbased on GPS clock signals at the edge device 122. In response, videodecoder can adjust a buffer size, such as a de-jitter buffer used in thevideo decoder 152 or the transceiver module 130 based on the networkjitter parameter, increasing the buffer size when greater network jitteris indicated and reducing the buffer size when less network jitter isindicated.

As discussed in conjunction with FIG. 3, edge device 122 can use timingdata derived from GPS signals 126 to generate authentication dataincluded in video signal 109. In particular, edge device 122 can obtainreal-time clock signals such as a time and that can be embedded asauthentication data in the video signal 109. In an embodiment of thepresent invention, decoder 152 includes an authentication routine thatcompares the time and date from the authentication data of video signal109 to its own time and date, generated locally by GPS receiver 160. Ifthe time and date included in the authentication data compare favorablyto locally generated timing (such as when the difference between thelocally generated time and date and the authentication is less than anauthentication threshold, the video signal 109 can be authenticated andthe playback of video signal by mobile video device 110 can be enabled.If however, the time and date included in the authentication data varyfrom the locally generated time and date by more than the authenticationthreshold, the playback of video signal 109 by mobile video device 110can be disabled.

As further discussed in conjunction with FIG. 3, location data receivedvia mobile device feedback 112 can be used to generate location-basedauthentication data that is embedded in the video signal 109. Videodecoder 152 can include an authentication routine that compares thelocation data from the authentication data of video signal 109 to itsown location data, such as GPS data 162 generated by GPS receiver 260.If the location data included in the authentication data comparesfavorably to GPS data 162 the video signal 109 can be authenticated andthe playback of video signal 109 by mobile video device 110 can beenabled. If however, the location data included in the authenticationdata varies from the GPS data 162 by more than an authenticationthreshold such as 1 mile, 5 miles or some greater or lesser distancebased on the desired level of security, the playback of the video signal109 by the mobile video device 110 can be disabled.

FIG. 7 presents a block diagram representation of a mobile video device111 in accordance with another embodiment of the present invention. Inparticular, mobile video device 111 includes many similar elements tomobile devices 110 and 110′ described in conjunction with FIGS. 6 and 7that are referred to by common reference numerals. Further, mobiledevice can include the many functions and features of mobile devices 110and 110′. In addition, mobile device 111 includes a input/output module190 and a video playback module 175 having a memory 180 and processingmodule 182 that executes an application for storing selected videosignals 109 as a plurality of stored video files and playing back thesevideo files. Input/output module 190 is a user interface module thatincludes one or more buttons, a keyboard, keypad, a click wheel, touchscreen, a microphone, speaker and/or other user interface devices thatallow the video playback module 175 to interact with the user byproviding prompts either directly or via screen displays that aregenerated by video playback module 175 and displayed on video displaydevice 140, to receive commands and other interface data 192 in responseto actions of a user of mobile video device 111.

In an embodiment of the present invention, processing module 182 can beimplemented using one or more microprocessors, micro-controllers,digital signal processors, microcomputers, central processing units,field programmable gate arrays, programmable logic devices, statemachines, logic circuits, analog circuits, digital circuits, and/or anydevices that manipulates signals (analog and/or digital) based onoperational instructions that are stored in a memory module, such asmemory 180. When processing module 182 is implemented with two or moredevices, each device can perform the same steps, processes or functionsin order to provide fault tolerance or redundancy. Alternatively, thefunction, steps and processes performed by processing module 182 can besplit between different devices to provide greater computational speedand/or efficiency. The associated memory module may be a single memorydevice or a plurality of memory devices. Such a memory device may be aread-only memory, random access memory, volatile memory, non-volatilememory, static random access memory (SRAM), dynamic random access memory(DRAM), flash memory, cache memory, and/or any device that storesdigital information. Note that when the processing module 182 implementsone or more of its functions via a state machine, analog circuitry,digital circuitry, and/or logic circuitry, the memory module storing thecorresponding operational instructions may be embedded within, orexternal to, the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry.

In operation, video playback module 175 can receive commands from a userto store a video signal 109 as a digital video file in memory 180. Theuser can also navigate the stored video files and a select a storedvideo file for playback. During playback, processing module 182 convertsthe stored video file to a video signal that is provided to videodecoder 152 that operates as described in conjunction with a receivedvideo signal 109 to generate a decoded video signal 154 for display ondisplay device 140. I/O module 190 optionally provides one or moreplayback control buttons such as stop, pause, fast forward, rewind, slowmotion, etc., that generate interface data 192 used by processing module182 to control the playback of a stored video file in response to usercommands. In addition, video playback module 175 generates navigationdata for each stored video file that can be used in a video navigationroutine that allows a user to select a stored video file for playbackbased on the navigation data and based on interface data 192 generatedin response to the action of a user.

In an embodiment of the present invention, the navigation data includesa still image or video clip, such as an opening shot, a title shot, anopening clip or other still image or video clip derived from the one ofthe plurality of stored video files or some other graphics object orgraphics data such as an icon, animation, or other graphicalrepresentation. The navigation data is stored in association with thecorresponding stored video file and used to generate selectable promptsdisplayed on video display device 140, such as thumbnail clips or imagesof the stored video files. These selectable prompts can then be selectedby the user via a touch screen, pointer or other selection mechanism ofI/O module 190.

Further navigation data for the stored video files can include textderived from the one of the plurality of stored video files. Forinstance, the audio track of a stored video file can be processed byprocessing module 182 using a speech recognition routine to generatetext such as keywords or phrases that are indexed and stored asnavigation data in association with the corresponding stored video file.In particular, some portion or all of an audio track is converted tosound signals that are processed by the speech recognition engine withrecognized words being stored, indexed as navigation data associatedwith the stored video file that contains the audio track. Similarly, thetext from close captioning data or text-based metadata such as title andcontent information that is received in conjunction with video signal109 can be indexed and stored as navigation data. In these embodiments,a user can search for a particular stored video file by inputting asearch term, keyword or other text that is compared with the navigationdata for the stored video files to find one or more matches.

In an embodiment of the present invention, input/output module 190includes a microphone and the user of mobile video device 111 canverbally enter interface data 192 such as commands and other input thatis translated by a speech recognition routine of processing module 182.In particular, text associated with particular stored video file thatthe user wishes to search for can be entered by speaking the particularword or words to the device. The speech recognition routine can convertthese spoken words to text that is used to locate one or more matchingstored video files based on their associated navigation data. Inaddition, other commands such as “search”, “play”, “pause”, etc. can beentered by the user as speech commands that are recognized by the speechrecognition routine. In one implementation, a speaker independent speechrecognition routine is implemented that can be used for both generatingnavigation data for stored video filed based on their associated audiotrack and for converting user speech to search text and commands.Alternatively, a speaker dependent speech recognition routine can beimplemented for interpreting user speech that operates based on trainingsets or other learned data for a particular user.

FIG. 8 presents a pictorial representation of a mobile device 200 inaccordance with another embodiment of the present invention. Inparticular a mobile device 200 is shown, such as mobile video device110, 110′ or 111 with a particular screen shot on a display screen 202,such as video display device 140, relating to a search mode of thedevice used for locating stored video files associated with a particulartext search string. In this mode of operation the user is prompted toenter a word or phrase, either by speaking the word or typing it onkeypad 204. In this case, the user has entered to word “Trees” and issearching for a stored video file containing video content relating totrees.

FIG. 9 presents a pictorial representation of a mobile device 200 inaccordance with another embodiment of the present invention. Inparticular, a further example screen shot is shown relating whereinmobile device 200 includes a touch screen. In this example, screen shot206 of video display device 140 displays four images such as video clipsor still images that are generated from navigational data stored inconjunction with four corresponding stored video files. The user selectsa particular one of the four stored video files for playback by touchingthe image on the touch screen that correspond to the stored video filethat the user wishes to play.

In an embodiment of the present invention, the particular four storedvideo were chosen based on a search routine run by processing module 182on the text entered from screen shot 202 of FIG. 8. In particular, whenthe user entered to the search string “trees” the search routinesearched text portions of navigational data associated with the storedvideo files to locate stored video files having text that included theword “trees”. In the alternative or in addition, the still images and/orvideo clips included in the navigational data associated with the storedvideo files can be used directly as a search tool to present indicationsof stored video files for selection by the user.

FIG. 10 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-9. In step 400, a device parameter is receivedfrom a remote device. In step 402, a video stream is received from avideo source. In step 404, video signal is generated by adjusting thevideo stream in accordance with the device parameter. In step 406, thevideo signal is transmitted to the remote device.

In an embodiment of the present invention, the device parameter caninclude a device resolution, a screen size, a display setting, adecoding error feedback parameter and/or a power state of the remotedevice. Step 404 can include adjusting the video stream based on aduration of the video stream so that the entire video stream can beviewed by the remote device, based on the power state, transcoding thevideo stream from a first video format to a second video format, and/oradjusting at least one of: the frame rate, the pacing, the bandwidth,and the color depth.

FIG. 11 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-10. In step 410, a device parameter of a mobiledevice is transmitted to an edge device of a video transmission networkvia an RF communication channel. In step 412, a video signal is receivedvia the RF communications channel, wherein the video signal is adjustedby the edge device based on the device parameter. In step 414, the videosignal is played in accordance with the device parameter.

In an embodiment of the present invention, the device parameter includesat least one of: a device resolution, a screen size, a display settingand/or a power state of the remote device. Step 414 can includegenerating a decoding feedback error parameter based on a decoding ofthe video signal and the device parameter can also include the decodingerror feedback parameter.

FIG. 12 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-11. In step 420, network global positioningsystem (GPS) signals are received. In step 422, a video signal istransmitted from a network module to a remote device that includes timestamps that are based on the network GPS signals. In step 424, the videosignal is received at a remote device. In step 426, the video signal isplayed at the remote device based on local timing generated from localGPS signals. In an embodiment of the present invention, the network GPSsignals are received from a GPS receiver.

FIG. 13 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-12 and in particular with the method of FIG.12. In step 430, a device parameter is transmitted from the remotedevice to the network module that indicates that local GPS signals areavailable. In an embodiment of the present invention, the network moduleincludes the time stamps that are based on the network GPS signals whenthe device parameter indicates that local GPS signals are available.Further, the network module can reduce the frequency of the time stampswhen the device parameter indicates that local GPS signals areavailable.

FIG. 14 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-13. In step 440, a video signal is receivedthat includes time stamps from a network module. In step 442, local GPSsignals are generated. In step 44, the video signal is played based onlocal timing generated from GPS signals.

FIG. 15 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-14 and in particular in conjunction with themethod of FIG. 14. In step 450, a device parameter is transmitted to thenetwork module that indicates that local GPS signals are available.

FIG. 16 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-15. In step 460, network timing data isreceived. In step 462, a video signal is transmitted to a remote devicethat includes authentication data that is based on the network timingdata. In step 464, the video signal is received at the remote device. Instep 466, the play of the video signal is authenticated based on localtiming data.

In an embodiment of the present invention, the network timing data isreceived at an edge device and/or received from a GPS receiver. In step466, the play of the video signal can be authenticated by comparing theauthentication data to the local timing data, and can be authenticatedwhen the difference between the authentication data and the local timingdata compares favorably to an authentication threshold. The local timingdata can be generated by a GPS receiver.

FIG. 17 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-16. In step 470, a video signal is receivedthat includes authentication data. In step 472, the play of the videosignal is authenticated based a local timing data. In step 474, thevideo signal is played, when authenticated.

In an embodiment of the present invention, step 424 authenticates theplay of the video signal by comparing the authentication data to thelocal timing data and can authenticate the play of the video signal whenthe difference between the authentication data and the local timing datacompares favorably to an authentication threshold.

FIG. 18 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-17 and in particular for use with the method ofFIG. 17. In step 480, the local timing data is generated based on GPSdata.

FIG. 19 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-18. In step 490, location data is received froma remote device. In step 492, a video stream is received from a videosource. In step 494, a video signal is generated based on the locationdata. In step 496, the video signal is transmitted to the remote device.

In an embodiment of the present invention, the network module includesan edge device. Step 494 can include adjusting a format of the videosignal based on the location data and/or generating authentication databased on the location data and embedding the authentication data in thevideo signal.

FIG. 20 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-19 and in particular for use in conjunctionwith the method of FIG. 19. In step 500, the transmission of the videosignal is selectively enabled based on the location data.

FIG. 21 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-19 and in particular for use in conjunctionwith the method of FIGS. 19 and 20. In step 510, a fee for thetransmission of the video signal is selected based on the location data.

FIG. 22 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-9. In step 520, location data is generated. Instep 522, the location data is transmitted to a network module. In step524, a video signal is received from the network module over at leastone RF communications channel, wherein the video signal is adjustedbased on the location data. In step 526, the video signal is played.

In an embodiment of the present invention, the network module adjusts aformat of the video signal based on the location data. In addition, thevideo signal can include authentication data based on the location data.

FIG. 23 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-22 and in particular in conjunction with themethod of FIG. 22. In step 530, the play of the video signal isauthenticated by comparing the authentication data and the locationdata.

FIG. 24 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-23. In step 540, a plurality of video signalsare received from a network. In step 542, selected ones of the pluralityof video signals are stored as a plurality of stored video files. Instep 544, video navigation data is generated for the plurality of storedvideo files. In step 546 at least one of the stored video files isselected for playback based on the video navigation data and based oninterface data generated in response to the action of a user.

In an embodiment of the present invention, the video navigation data forone of the plurality of stored video files includes a still imagederived from the one of the plurality of stored video files, a videoclip derived from the one of the plurality of stored video files, and/ortext derived from the one of the plurality of stored video files and/orgraphics data, a graphics object. In addition, the navigation data canbe generated based on a speech recognition of an audio track from theone of the plurality of stored video files, based on closed captioningdata from the one of the plurality of stored video files or based onmetadata from the one of the plurality of stored video files.

In an embodiment of the present invention, the interface data isgenerated by the user touching a touch screen in response to a displayof the navigation data that includes at least one of: a video clip and astill image, based a speech recognition of spoken words of the user,and/or based a speech recognition of spoken commands of the user.

FIG. 25 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-24. In step 550, a video signal is receivedfrom a network module, wherein the video signal is encoded based on GPSsignals. In step 552, local GPS signals are generated. In step 554, thevideo signal is decoded based on local timing generated from local GPSsignals.

FIG. 26 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with the method of FIG. 25. In step 560, a network jitterparameter is measured based on the local timing generated from GPSsignals. In step 562, a buffer size is adjusted based on the networkjitter parameter.

While the foregoing description of a global clock has centered on theuse of a GPS clock signal, other global clock signaling, real-time orotherwise, can likewise be used. In particular other RF global clocksignals can be used in accordance with the present invention. Further,while the foregoing description has focused on the transmission of videosignals 109 to a mobile video device, such as mobile video device 110,110′ or 111, likewise other video devices, such as set-top boxes, videoplayers, televisions or other video devices can likewise be used inaccordance with the present invention.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “coupled to” and/or “coupling” and/or includes direct couplingbetween items and/or indirect coupling between items via an interveningitem (e.g., an item includes, but is not limited to, a component, anelement, a circuit, and/or a module) where, for indirect coupling, theintervening item does not modify the information of a signal but mayadjust its current level, voltage level, and/or power level. As mayfurther be used herein, inferred coupling (i.e., where one element iscoupled to another element by inference) includes direct and indirectcoupling between two items in the same manner as “coupled to”. As mayeven further be used herein, the term “operable to” indicates that anitem includes one or more of power connections, input(s), output(s), etcetera., to perform one or more its corresponding functions and mayfurther include inferred coupling to one or more other items. As maystill further be used herein, the term “associated with”, includesdirect and/or indirect coupling of separate items and/or one item beingembedded within another item. As may be used herein, the term “comparesfavorably”, indicates that a comparison between two or more items,signals, et cetera, provides a desired relationship. For example, whenthe desired relationship is that signal 1 has a greater magnitude thansignal 2, a favorable comparison may be achieved when the magnitude ofsignal 1 is greater than that of signal 2 or when the magnitude ofsignal 2 is less than that of signal 1.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention. One of average skill in the art will also recognize that thefunctional building blocks, and other illustrative blocks, modules andcomponents herein, can be implemented as illustrated or by discretecomponents, application specific integrated circuits, processorsexecuting appropriate software and the like or any combination thereof.

1. A video transmission system comprising: a network module thatreceives network global positioning system (GPS) signals and thattransmits a video signal to a remote device that includes time stampsthat are based on the network GPS signals; and a remote device, incommunication with the network module, that receives the video signaland that plays the video signal based on local timing generated fromlocal GPS signals.
 2. The video transmission system of claim 1 whereinthe network module includes an edge device.
 3. The video transmissionsystem of claim 1 wherein the network module receives the network GPSsignals from a GPS receiver.
 4. The video transmission system of claim 1wherein the remote device transmits a device parameter to the networkmodule that indicates that local GPS signals are available.
 5. The videotransmission system of claim 4 wherein the network module includes thetime stamps that are based on the network GPS signals when the deviceparameter indicates that local GPS signals are available.
 6. The videotransmission system of claim 5 wherein the network module reduces thefrequency of the time stamps when the device parameter indicates thatlocal GPS signals are available.
 7. A mobile video device comprising: anRF receiver that receives a video signal that includes time stamps froma network module; a GPS receiver that generates local GPS signals; avideo playback module, coupled to the RF receiver and the GPS receiver,that plays the video signal based on local timing generated from GPSsignals.
 8. The mobile video device of claim 7 further comprising: atransmitter that transmits a device parameter to the network module thatindicates that local GPS signals are available.
 9. A method comprising:receiving network global positioning system (GPS) signals; transmittinga video signal from a network module to a remote device that includestime stamps that are based on the network GPS signals; receiving thevideo signal at a remote device; playing the video signal at the remotedevice based on local timing generated from local GPS signals.
 10. Themethod of claim 9 wherein the network GPS signals are received from aGPS receiver.
 11. The method of claim 9 further comprising: transmittinga device parameter from the remote device to the network module thatindicates that local GPS signals are available.
 12. The method of claim11 wherein the network module includes the time stamps that are based onthe network GPS signals when the device parameter indicates that localGPS signals are available.
 13. The method of claim 11 wherein thenetwork module reduces the frequency of the time stamps when the deviceparameter indicates that local GPS signals are available.
 14. A methodcomprising: receiving a video signal that includes time stamps from anetwork module; generating local GPS signals; and playing the videosignal based on local timing generated from GPS signals.
 15. The methodof claim 14 further comprising: transmitting a device parameter to thenetwork module that indicates that local GPS signals are available. 16.A method comprising: receiving a video signal from a network module,wherein the video signal is encoded based on GPS signals; generatinglocal GPS signals; and decoding the video signal based on local timinggenerated from local GPS signals.
 17. The method of claim 16 furthercomprising: measuring a network jitter parameter based on the localtiming generated from GPS signals; and adjusting a buffer size based onthe network jitter parameter.